INFO: task syz.1.1142:10115 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1142 state:D stack:28752 pid:10115 ppid:9700 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5393 [inline] __schedule+0x15ae/0x4700 kernel/sched/core.c:6722 schedule+0xbd/0x170 kernel/sched/core.c:6796 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6855 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747 sync_bdevs+0x1a4/0x320 block/bdev.c:1077 ksys_sync+0xc6/0x170 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f29d8b9f559 RSP: 002b:00007f29d9a6f028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f29d8e26090 RCX: 00007f29d8b9f559 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f29d8e26090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f29d8e26128 R14: 00007f29d8e26090 R15: 00007ffc38800a08 Showing all locks held in the system: 1 lock held by rcu_tasks_trace/15: #0: ffff8880b8d3c258 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:570 2 locks held by kworker/1:1/28: #0: ffff888018872d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #0: ffff888018872d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 #1: ffffc90000a4fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #1: ffffc90000a4fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 1 lock held by khungtaskd/29: #0: ffffffff8df322e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8df322e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8df322e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6669 2 locks held by kworker/u4:3/49: 2 locks held by kworker/u4:7/1097: 2 locks held by kworker/u4:17/3531: #0: ffff8880b8d3c258 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:570 #1: ffff8880b8d28a00 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline] #1: ffff8880b8d28a00 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2202/0x4700 kernel/sched/core.c:6717 2 locks held by getty/5535: #0: ffff888032f7a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032862f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217 1 lock held by udevd/6058: #0: ffff8880228ab4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801 3 locks held by kworker/0:5/6176: #0: ffff888018870d38 ((wq_completion)events#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #0: ffff888018870d38 ((wq_completion)events#2){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 #1: ffffc9000339fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline] #1: ffffc9000339fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734 #2: ffff88801cb67240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x285/0x32c0 drivers/net/netdevsim/fib.c:1491 1 lock held by syz.1.1142/10115: #0: ffff8880228ab4c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1a4/0x320 block/bdev.c:1077 1 lock held by syz.2.1985/13928: #0: ffff888079729e20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline] #0: ffff888079729e20 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x166/0x3f0 mm/util.c:571 1 lock held by syz.2.1985/13929: 1 lock held by syz.6.1987/13935: #0: ffff888068a3a620 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #0: ffff888068a3a620 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline] #0: ffff888068a3a620 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x82/0x210 net/socket.c:1421 2 locks held by dhcpcd-run-hook/13953: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf59/0xfa0 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3531 Comm: kworker/u4:17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Workqueue: bat_events batadv_nc_worker RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:60 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline] RIP: 0010:kasan_check_range+0x52/0x290 mm/kasan/generic.c:187 Code: f9 49 c1 e9 2f 41 81 f9 ff ff 01 00 0f 82 ff 01 00 00 49 89 ff 49 c1 ef 03 49 ba 00 00 00 00 00 fc ff df 4f 8d 1c 17 49 ff c8 <4d> 89 c1 49 c1 e9 03 48 bb 01 00 00 00 00 fc ff df 4d 8d 34 19 4d RSP: 0018:ffffc9000d29f6c8 EFLAGS: 00000086 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8168e78d RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff91fe55e0 RBP: ffffc9000d29f948 R08: ffffffff91fe55e7 R09: 000000000001ffff R10: dffffc0000000000 R11: fffffbfff23fcabc R12: 0000000000000000 R13: ffff88802fcc4708 R14: 000000000000070c R15: 1ffffffff23fcabc FS: 0000000000000000(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563d90c2a950 CR3: 000000007d5e1000 CR4: 00000000003506e0 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class kernel/locking/lockdep.c:228 [inline] check_wait_context kernel/locking/lockdep.c:4826 [inline] __lock_acquire+0xa4d/0x7eb0 kernel/locking/lockdep.c:5121 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5790 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] batadv_nc_purge_paths+0xe2/0x3a0 net/batman-adv/network-coding.c:442 batadv_nc_worker+0x322/0x600 net/batman-adv/network-coding.c:720 process_one_work kernel/workqueue.c:2657 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293